Chiral auxiliaries have been extensively used in asymmetric syntheses. Traditionally, the N-acyl 2-oxazolidinones have been synthesized by lithiating the oxazolidinone with n-butyl lithium at -78.degree. C., followed by acylating with an acyl chloride. N-acyl sultams have been synthesized by deprotonation with NaH followed by N-acylation with an acyl chloride. Also, two step procedures have been used to convert the oxazolidinone or sultam to the trimethylsilyl derivative, followed by reaction with excess acyl chloride in refluxing toluene. Neither of these synthesis schemes is particularly useful when the acyl side chain contains substituent groups that are reactive. Also, it takes an inordinately long time for the reaction to run to completion. The present invention overcomes the disadvantages in these processes.